As I approach a second full decade of being a Catholic, having entered the Church in 1997, I sometimes reflect on the arch of our journey from Fundamentalism to Evangelicalism to Catholicism. As I’ve indicated before, my wife and I had to work through Catholic beliefs about Mary, the saints and the sacraments. However, one subject that seemed to hover in the background — perhaps because it wasn’t as obviously controversial — was that of ecclesiology, the nature and mission of the Church. Yet one’s understanding of the Church shapes and colors nearly everything else.

We must understand that the Church is not a social club, a political party or movement, or a mere human institution. The Church was founded by Christ, states the catechism, for one ultimate purpose: “for the sake of communion with [God’s] divine life.” The Church “is the goal of all things” (CCC, No. 760). That simple statement alone should give us pause. The Church, which is the body of Christ, was founded by our Lord so that men and women can be redeemed, made holy and thus, by the power of the Holy Spirit, be transformed into children of God.

Today’s Gospel contains the second of two appearances of the word ecclesia, or “church,” in the Gospels; it also appears in Matthew 16:18, in the Gospel reading heard two weeks ago. In both cases, the word “church” was uttered by Jesus in the context of apostolic and ecclesial authority. In Matthew 16, Peter, the Rock, was bequeathed unique authority to be the vicar, or prime minister, of the Davidic king, Jesus Christ. In Matthew 18, the issue is practical: how to resolve conflicts within the Church. What are we to do when a fellow Christian has sinned against us?

The Church, of course, has canon law, and it has an important role. But the greatest law — or the thing that perfectly fulfills any and all laws — is love. St. Paul is quite clear about this in his letter to the Christians in Rome, saying that “the one who loves another has fulfilled the law” and that “whatever other commandment there may be, are summed up in this saying, namely, ‘You shall love your neighbor as yourself.’” True love is sacrificial; it desires the good of others. It seeks to act with eternity in mind, without concern for immediate satisfaction or quick justice. Being a child of God and a member of his household and family is not easy, as we all know. It might even involve strong rebuke and firm discipline.

Yet the steps that Jesus outlined were not aimed, of course, at retribution, but reconciliation. First, he instructed to try talking to the offending brother alone, away from public scrutiny. If he doesn’t listen, bring along “one or two others” so the facts of the matter can be fairly discussed, with testimony from witnesses — a practice rooted in the Torah (cf. Dt 19:15). If such attempts do not settle the matter, the problem goes before the Church. The catechism puts this in proper context: “Reconciliation with the Church is inseparable from reconciliation with God” (No. 1445). If the Church was founded by Christ and has been entrusted with his authority, then we should recognize she exists and works for our good, so we can be in right relationship with him.

Anyone refusing to hear or submit to proper Church authority is to be kept from full communion — for his sake and that of the Church. Excommunication, then, is therefore an act of love, meant to save the sinner from eternal spiritual destruction.